Research On Water Resources Optimalallocation Of Shi Yang River Basin In Ecological

Shi yang River drainage Basin is one of the three biggest continental river ofHexi corridor in Gansu province. Nowadays, it has the highest population density,developed economy and society, the highest degree of water development andutilization, the most prominent environmental problem in the northwest of china. Dueto the unreasonable water resource allocation, the ecological-used water was occupiedby irrigation of crops and used in social economy. Therefore, the yield of waterdecreased in Minqin oasis of downstream, the groundwater declined, the naturalvegetation depending on groundwater fell off, the oasis shrink, which caused a seriesof environmental problems, such as land desertification, desertification, extendedsalinization. Theses problems threaten the sustainable development of the basis, aswell as threaten the survival of the local people. Research on water resources optimalallocation of Shi yang River Basin in ecological, which gives a scientific basis forrational allocation and efficient utilization of regional water resources.The article studied by stimulating the reasonable allocation with methods inevaluating the amount of ecological water for natural vegetation, irrigation water ofcrops in arid region, ecological water of natural vegetation, irrigation water of cropsand water used in industry and life. It is theoretically based on evaporation fromphreatic water as well as area-quota water demand, combining with remote sensingtechnology and ArcGIS method so that the land use date of Shi yang River Basin in1987,2000, and2010can be gained, in which the author can extract the areas ofdifferent vegetational forms. Finally, the author evaluated the water demand of naturalvegetation and irrigation of crops with three levels of ecological water situation: thesmallest; moderate and largest. The total amount of industrial and agriculture wateruse in each county can be calculated according to the yield of water based onmillion-GDP and the per capita of domestic consumption. Through the stimulation insix situations with different water demand, hopefully, the most reasonable waterallocation model of counties based on the objects of ecological protection around Shiyang River Basin in2020can be achieved. It showed that the growth of natural vegetation of the Shi yang River Basindegenerated gradually, and the ecological water demand of each county continued todecrease from1987, especially for MinQin County. However, the cultivated area ofcrops as well as the water used for irrigation were increased. Besides that, it is clearlyto be seen that the plantation structure of the six crops changed from mainly plantingfood crop to a variety of crops, which can get the maxim benefits. This kind of changereflect that the the plantation structure of crops is effected by the development of thesociety and economy so that the plantation structure of crops in Shi yang River Basinbecome more and more reasonable. Nothing is better than the significant change ofindustrial water demand, which caused the biggest change of water demand in thebasin. Jin Chuan region is worthy of the big industry region, whose industrial waterdemand is far over the average level in basin.Water resources optimal allocation of Shi yang River Basin in different modelsituations, which is under the premise of guaranteeing the good-healthy growth ofecological environment in basin. From the result of water resources optimal allocationin six different situations, it suggested that the essence of water resources optimalallocation in Shi yang River Basin is the contest between the water for crop irrigationand for natural vegetation as ecological water. That means we need to ensure the foodsecurity under the premise of ecological safety. The total amount of water needed inSix kinds of simulation under the situation of water resources allocation can bebetween5.69×108m3to6.84×108m3as the different targets of ecological protectionwater needed for irrigation.In condition of the Shi yang River Basin is not only the eco-fragile region ofnorthwest but also the important production base of commodity grain in china.Therefore, this study promote a optimization scheme, which based on the aims ofrecovering the growth condition of natural vegetation in1987, and water for crops canbe80%according to the total amount of water under stimulated allocation and thewater demand pattern. considering the actual ecological condition in MinQin, LiangZhou, Gu Lang, Jin Chuan, the author adjust their ecological water demand referringto the average water demand in all the departments. In this way, the result of waterresources optimal allocation in Shi yang River Basin in2020can be achieved. It showed that in2020, the total water need to be6.75×108m3, in which water forirrigation is3.04×108m3, which can be the biggest host for water using. The rest ofwater using in forest, grassland, and industry can be totally50%of the total waterdemand in the basin. The stimulated optimal allocation not only thinks about thevegetation ecological water under the ecological reserved objects, but also the waterdemand for the well development of economy and people’s lives. This stimulatedoptimal is rational and scientific, which also give a guide for the future waterallocation in the basin.